This invention is generally directed to an improved ventilated cage and rack system, and in particular, to a ventilated cage and rack system which supplies air and water to an animal cage within a rack system.
An animal cage which supplies air directly to the cage is known in the art as illustrated in U.S. Pat. No. 4,593,650. This cage includes a cage bottom and cage bonnet. The cage bonnet has an open top with a filter extending across the top to allow the exhaust of gases. A filter having a tubular fitting connected to a pressurized air source is supported in the filter bonnet to provide pressurized air into the cage. This prior art cage has been less than satisfactory. The cage suffers from the disadvantage that a water supply must be provided within the cage necessitating the opening of the cage periodically to provide a water supply to the test animal thereby increasing the chances for contamination of the test animal by reducing the amount of isolation of the animals in the cage. Additionally, the heavier particles such as ammonia are less likely to be forced out of the cage because the air is forced through the top half of the cage and not the bottom where the heavier ammonia particles are located.
A ventilated rack system is known in the art as illustrated in U.S. Pat. No. 4,365,590. This rack system includes a hollow housing having a plurality of shelves for supporting cage level barrier cages therein. A low pressure air plenum extending along one side of the cage rack communicates with one side of each of the shelf compartments. The other side of the rack system includes a filtered airport in the openings which communicates with the room interior to provide a low pressure negative air flow across animal cages. Additionally, the a watering system is provided to dispense water through individual valves provided outside the individual animal cages. This ventilated rack has been less than satisfactory. It suffers from the disadvantage that it does not simultaneously provide air into the animal cage. Additionally, because the water is delivered outside of the cage, the animal must extend its head outside of the isolated cage area exposing itself to the environment and possible contamination.
Both the prior art ventilated cage and prior art ventilated rack suffer from the additional shortcomings that humidity, ammonia and carbon dioxide generated by the animal build up within the cage affecting the animal.
Accordingly, a combined ventilated cage rack system which is of simple structure and prevents the build up of ammonia, humidity and carbon dioxide within the cage and its escape into the room is desired.